Lever control assemblies are commonly used to control throttle and transmission functions in various types of vehicles. Often such assemblies are used in marine craft for operating the various functions of an outboard or inboard engine. Generally, the assembly includes a housing for supporting the assembly on a support structure. An actuator, including a lever, is pivotally mounted on the housing and is operatively connected to a core element or rod for remotely controlling some engine function. Examples of such assemblies are taught by the U.S. Pat. No. 3,871,244 to Gressard et al, and U.S. Pat. No. 4,191,064 to Houk et al. The lever of the assembly often extends through a slot in the housing. It is desirable to prevent foreign particles from entering the housing through the slot. A slot cover may be mounted on the lever to be movable therewith to prevent foreign particles from entering the slot. The assembly disclosed by the Houk et al patent includes wipers at each end of the slot which contact a movable slot cover. A problem arises from foreign particles entering the housing along the length of the slot cover. The instant invention overcomes this problem by including means for perfecting a seal completely about the slot and slot cover.